Ejector mechanism for molding machines



J. D. GUELPH EJECTOR MECHANISM FOR MOLDING MACHINES Oct. 18, 1949.

3 Sheets-Sheet 1 Filed Jan. .30, 1947 A TORNE Y Oct. 18, 1949. J DGUELPH 2,485,283

EJECTOR MECHANISM FOR MOLDING MACHINES Filed Jan. 30, 1947 3Sheets-Sheet 2 IN VEN TOR.

%/ dO/WOGUELRH BY v Oct. 18, 1949. J. D. GUELPH EJECTOR MECHANISM FORMOLDING MACHINES 3 Sheets-Sheet 3 Filed Jan. 30, 1947 I INVENTOR.dam/0.62151. PH BY ATTORNEY Patented Oct. 18, 1949 EJECTOR MECHANISM FORMOLDING MACHINES John D. Guelph, Paterson, N. J-., assignor to A. R. D.Corporation, New York, N. Y., a corporation of New York ApplicationJanuary 30, 1947, Serial No. 725,381

Claims.

This invention relates to molding machines. More particularly, itrelates to a new and improved ejecting mechanism for molding machines.

In conventional injection-molding machines wherein the molding cavity isformed by a pair of complemental relatively movable die members, thecasting is removed from the die by ejector pins after the die membershave been separated. In general, in such machines the ejector pins arecarried on an ejector plate which, in turn, is secured to an ejector rodprojecting from the movable platen (mold clamp). The ejector rod, as themold clamp moves in its opening stroke, strikes and engages a stationarypart of the machine whereby, during further descent of the movableplaten, the ejector plate and the pins carried thereby are actuated toeject the molding from the die.

In conventional injection-molding machines wherein cores are utilized,the molding is either stripped from the cores by the ejecting mechanismpreviously described, or the molding together with the cores are ejectedby the ejecting mechanism and thereafter the cores manually pulled ormoved by means dependent on the stroke.

In each of the aforementioned injection-molding machines, the removal ofthe molding from the die is efiected during and is dependent on theopening stroke of the mold clamp.

An object of thisinvention is to provide an ejecting mechanism for amolding machine which is operative independently of the stroke of theopening clamp.

Another object of this invention is to rovide an ejecting mechanism foran injection-molding machine which can be operated at any position ofthe clamp and independently of the stroke of said clamp.

An additional object of this invention is to provide a core puller foran injection-molding apparatus which is operative independently of thestroke of the opening clamp.

A further object of this invention is to provide a core puller for aninjection-molding apparatus which can be operated in any position of theclamp and independently of the stroke of said clamp.

A still further object of this invention is to provide a core puller andan ejector for an injection-molding apparatus, said core puller andejector being separately operated in the desired sequence andindependently of the stroke of the opening clamp.

Other and additional objects Will become apparent hereinafter.

The objects of this invention are accomplished, in general, byassociating acore plate and an ejector plate with the die member carriedby the movable clampof an injection-molding machine, and providingseparate means to actuate the core plate and the ejector plate in thedesired sequence independently of each other and the stroke of theopening clamp.

The ejector plate is secured to one end of a piston rod, the other endof which is secured to an ejector plate piston slidably mounted in anouter cylinder disposed in a centrally located opening in the movableplaten. The outer cylinder is provided with appropriately located portsfor the delivery and discharge of fluid pressure whereby the ejectorplate piston is actuated in a vertical direction and the ejector platewill be moved up or down depending on the direction of movement of thepiston.

The ejector plate piston and piston rod are made hollow, and a second(inner) cylinder carried by the head of the outer cylinder is disposedtherein. A core plate piston is slidably positioned in the innercylinder, and the piston rod thereof is secured to the core plate. Theinner cylinder is provided with appropriately located ports for thedelivery and ejection of fluid pressure whereby th core plate piston isactuated in a vertical direction and the core plate moved up or downdepending on the movement of the piston to which it is connected.

Each of the pistons is separately controlled and actuated, with theresult that the core plate and the ejector plate are moved independentlyof each other and in the desired sequence. Also, each of the pistons canbe operated independently of the movement of the movable platen.

When the apparatus is employed for the production of solid castingswhich-do not require the utilization of cores, the core plate is omittedand the ejector plate is positioned on both the piston rods and eitherone can be operated to eiiect the ejecting action after the movableplaten has been opened to the desired position.

The invention will be more clearly understood by reference to thefollowing detailed description when taken in connection with theaccompanying drawings, in which:

Figure l is a perspective view, partly broken away, of aninjection-molding machine contain ing the core puller and ejector platemechanisms;

Figure 2 is a vertical section platen omitted; and

with the upper Figure 3 is a top plan view of the apparatus shown inFigure 2, the ejector box being omitted.

Referring now to the drawings wherein like reference numerals designatelike parts, the reference numeral I designates a plurality of rods whichare appropriately secured and fixedly mounted in the machine and onwhich a platen I2 is fixedly secured and a movable platen I4 isappropriately mounted for sliding movement thereon. An upper die memberI6 is appropriately removably secured to the under surface of the topfixed platen I2. The die member I6 is. provided with a passage I8 whichis connected to a ate (not shown) and into which the material tobemolded is introduced.

The upper die member I6 is designed to cooperate with a lower die member28. The two die members I6 and are complemental and, when in moldingposition as hereinafter more fully described, will provide a moldingcavity or cavities. of the desired shapes: and sizes.

The lower die member 20 is appropriately removably secured onto anejector box. 22, the bottom of which is seated on and adjustably securedto the lower platen I4. The bottom of the ejector box 22 isprovided withside flanges 23 which are adapted to be engaged by spaced clamps 24.Each clamp 24 is provided with a T-shaped tongue 25 which is slidablypositioned in a T-slot 26 in the lower platen and is secured in clampingposition by a lock screw 2.8. The lower platen I4 is secured at itsbottom to the top of a piston 30. which is actuated by hydraulic means,generally designated by the reference numeral 32-, inv the usual mannerto raise and lower the platen The ejector plate 34. issecured. to ahollow piston rod 38 which is secured at its lower end to a piston 40.The piston 40 is slidably positioned in. an outer cylinder 42 positionedin a central open-- ing in the. lower platen I4. The cylinder 42 isprovided at. the top thereof with an annular flange 4.4 which isdisposed in an annular recess in the top of the lower platen I4 andsecured therein by means of screws 46. A cylinder head 48 is threadedlysecured onto the bottom of the cylinder 42. The cylinder 42 and the head48 are provided with ports 58 and 52 respectively whereby pressure fluidcan be introduced and discharged for actuating the piston 40. A shoulder54 on the head 48. and a shoulder 56 on the cylinder 42 constitute stopswhich limit movement of the piston 40. in its downward and upwardmovements respectively.

The piston 40 and its extension (piston rod) 38. are hollow and receivean inner cylinder 68. In the; form shown, the inner cylinder 60 isformed integrally with and extends upwardly from the head 48. A piston62 is slidably positioned in the inner cylinder BI] and the piston rod64 thereof is secured at its upper end to a core plate 66, located inthe ejector box 22. The core plate 66.- is provided with cores 68.Approximately located ports communicate with the interior of the innercylinder whereby fluid pressure can be introduced and dischargedtherefrom and the piston actuated either up or down as desired.v In theform. shown, the head 48. is provided. with ports Ill and I2. The portIII leads to below the piston 62,. and the. port I2 is connected to thelower end of a passage I4 in the wall. of the inner cylinder 60.Thepassage I4 terminates at its upper end .4 in a passage I6 which leadsinto the interior of the inner cylinder 60 above the piston 62.

The ejector plate 34 is provided with a central hole in which the pistonrod 64 is slidably positioned. The piston 62 is limited in its downwardmovement by a shoulder on the head 48 and in its upward movement by astop 82. The stop 82 is formed at the lower end of a cylindrical member84 which is threaded into the inner cylinder 60 at the top thereof. Themember 84 is provided at the top thereof with an annular flange 86 whichis seated on the top edge of the inner cylinder 68. A bushing 88 isdisposed in the member 84. The bushing 88 is provided with an annularflange 98 which is seated on the flange 86. Screws 92 secure the bushingto the member 84.

A ring packing 94' is positioned between the lower end. of the bushing88 and the upper end of the stop 82. A ring packing 96 is positioned onan inner shoulder 98 of the outer cylinder 42 and is maintained inposition by a locking ring I08 secured tothe outer cylinder 42 by screwsI84. Another packing ring I06 is provided in the inner surface of thepiston 40 adjacent the bot tom thereof.

The ports 58 and 52 are connected to suitable conduits H8 and H2 which,in turn, are connected to a four-way valve H4. The four-way valve I I4is connected to a fluid pressure line H6 and to a line H8 leading to asump (not shown). The valve H4 is a conventional four-way valve and,when it is operated in one direction, fluid under pressure from the lineH6 is fed through the valve H4 into the line H2 to the port 52, and theline H0 is connected to the line I I8 leadingto the sump. Under theseconditions, the piston 40 is moved upwardly and the ejector plate ismoved upwardly. When the valve I-I I is operatedin the other direction,the piston 40 will be operated in the other direction, 1. e., thepressure fluid w-ili be directed from the line H'6- by the valve I-I4-through the line H0, and the ejected fluid will" be conducted from thecylinder by the line II=2 through the valve H4 to the line H8.

The ports I8 and I2 are connected respectively to conduits I26 and I22which lead to a conventional four-way valve I24. A line I26 leads-fluidunder pressure to. the valve I24, and a line I28 connected to. the valveI24 leads to a sump (not shown) When the valve isoperated in onedirection, the fluid: under pressure is fedthrough the line. I2Ilandthrough the port 10: whereby the piston. 62 ismoved upwardly. The fluidejected from the inner cylinder by the upward movement of. the. piston.62 is conducted. through the port I2 to the line I22 which is.connected. through the valve.- l24 to. the sump- Whenv the valve I24 is.

operated in. the other direction, the. movement of the piston 62 isreversed.

In operatiomthe desired: die member I6. is securedto the. upper platen=I2 and the. desired complemental die member 20 together with theappropriate ejector box. 22,. is. clamped. in proper position on. thelower platen I4. by meansv of the clamps. 24.. The ejector plate 34 issecured to the piston rod 38; of; the piston. 40 and the core plate. 66;is secured to. the. piston rod 64. of the piston 62. At this stage ofthe operation, the piston 62 is at the end of itsiupiwardastnoke and inposition sothat upon actuation it will move. in a. downward direction topull the. cores, and the piston 40. is; at. the end of its downwardstroke. and in position so that upon actuation thereof it will move inan upward direction and cause the ejecting pins to strip the moldingfrom the die. The hydraulic mechanism 32 is actuated to elevate thelower platen and clamp the die member IS in close intimate relationshipwith the die member 20. At this stage, the ejector plate 34 and the coreplate 66, together with their respective operating mechanisms, arepositioned as shown in Figure 2.

The plastic to be molded, which is previously preheated, is forced underpressure through the gate and through the passage I8 to fill the diecavities. After the molding has cooled sufficiently, the hydraulic means32 is actuatedso that it will cause the lower platen to descend andseparate the die members I6 and from each other.

At any desired time after the lower die member I 20 has separated fromthe die member I6, the valve I is operated so that fluid under pressureis fed from the line I26 through the line I22 and through the port I2,whereby the piston 62 is caused to descend and the cores are pulled.During this operation, the fluid ejected from-the inner cylinder is fedaway through the line I20 and directed into the line I28 by the valveI24. After the cores have been pulled, the valve H4 is ac-;

tuated so that fluid under pressure from line H6 is fed into the line II2 and into the outer cylinder through the port 52, whereby the pistonis moved upwardly, with the result that the ejector plate 34 also ismoved upwardly and the molding stripped from the dies. During thisoperation, the line III] is connected through the valve IM to the line II8. After the molding has been removed, the valves H4 and I24 are eachactuated to restore the ejector plate and the core plate to the originalmolding position, and the cycle of operations previously describedrepeated.

If desired, the core plate can be secured to the piston rod 38 and theejector plate secured to the piston rod 64.

Though hereinbefore the invention has been described as applied to aninjection-molding machine for the molding of articles requiring the useof cores, it is to be understood that the invention is not restrictedthereto. The invention is equally applicable for use ininjection-molding machines for molding solid articles which do notrequire the use of cores. In such an embodiment of the invention, thecore plate 66, together with the cores 68 described in the procedingembodiment, is omitted, and the ejector plate is disposed on both of thepiston rods. In such embodiment, both pistons are in position so that,upon actuation of either or both, the ejector plate will be movedupwardly.

In the embodiment described inthe preceding paragraph, after the moldingoperation and the molding has sufficiently cooled, the hydraulic means32 is actuated to move the lower platen downwardly whereby the diemembers are separated. After separation, the operator can operate eithervalve H4 or I24 or both, as desired, whereby the piston 62 or the piston40 is actuated to move in an upward direction. The movement of either orboth of the pistons will elevate the ejector plate whereby the moldingwill be ejected from the die.

As is apparent from the foregoing embodiments, the pistons and theiractuating mechanisms can be used without change with either dies havingboth ejecting means and a corepulling means, or dies having onlyejecting means. In general, the invention can be utilized to actuate anymechanism associated with the die in an injection-molding machine andwhich removes or aids' in removing the molding from the die cavity.

When the injection-molding machine is intended to produce only solidmoldings not requiring the use of cores, not only can the core plate beomitted but also the core plate piston and the actuating mechanismtherefor. In such a machine, the ejector plate can be secured to the onepiston. Preferably, the ejector plate is, in such embodiment, secured tothe piston 62 and the outer cylinder can also be omitted.

The invention, though it is admirably suitable for use withinjection-molding machines with or without cores, is not restrictedthereto. It can be utilized in molding machines of any type whereinthe'die members which form the molding cavity are movable relative toeach other and which utilize ejecting pins with or without core pullers.

In general, the invention can be applied to molding machines, such asinjection-molding machines, die casting machines, compressionmoldingmachines, transfer molding machines, powder metallurgy pressers, ceramiccompression pressers or the like, irrespective of whether the diemembers move relative to each other in a horizontal or verticaldirection.

The invention can be applied to molding machines irrespective of thesize of the moldings.

The ejection and core-pulling operations when used are efiectedseparately and independently of each other in the desired sequence.These operations are also effected independently of the movement of thelower platen and can be effected after the dies have been separated andthe lower platen is stationary. Of course, the operations in the propersequence can be efiected after separation and during the movement of thelower platen away from the upper platen.

Since it is obvious that various changes and modifications may be madein the above description without departing from the nature or spiritthereof, this invention is not restricted thereto except as set forth inthe appended claims.

I claim:

1. A molding machine comprising a pair of platens, a die member carriedby each of said platens, means to move one of said platens relative tothe other, a pair of concentric cylinders carriedby the movable platenand spaced radially to form an annular chamber therebetween, an annularpiston disposed in said chamber and slidable between said cylinders, asecond piston slidably disposed in the inner cylinder, an ejector platedirectly seated on one of said pistons, a core plate directly secured tothe other of said pistons, and means to actuate each of said pistonsindependently of the other.

2. A molding machine comprising a pair of platens, a die member carriedby each of said platens, means to move one of said platens relative tothe other, a pair of concentric cylinders carried by the movable platenand spaced radially to form an annular chamber therebetween, an annularpiston disposed in said chamber and slidable between said cylinders, asecond piston slidably disposed in the inner cylinder, an ejector platedirectly seated on one of said pistons, a core plate directly secured tothe other of said pistons, and means to actuate each of said pistonsindependently of the other and independently of the movement of themovable platen.

3. A molding machine comprising a pair of platens, a die member carriedby each of said platens, means to move one of said platens relaw securedto said. annular piston, asecondpiston.

slidably. disposed in the inner cylinder, core-- pulling means securedto the: second: pistom. and. means. to actuate; each of said pistons:inde-- pendently of each other and independently of: the movement: ofthemovable platen.

4.. A. molding machine comprising-a. pair.- of

platens, a die member carried by each or said.

platens, means to move one. of said platens relative to. the other, apair of concentric cylinders.

carried bythe movable; platen and spaced radiallyv to form an. annularchamber therebetween, an annular piston. disposed in said; chainher andslidable between. said cylinders, ejecting means. secured to saidannular piston, a second.

piston slidabl-y disposed in the inner cylinder, core-pulling meanssecured: to the second piston, said annular piston having a bottomsurface-t0 receive the fluid. thrust-from said annular cham her and:having an upwardly facing, outer annu-- lar shoulder forming with theouter cylinder an Numberannular.- chamberto receive fluid for forcing:said annular piston. downwardly; and fluid supply means. to. actuatesaidpistons independently of the movement oi'EJthe movable: platen.

daA molding machine. comprising a pair of platens. at cliemember.carried by each of said platens, means; to .mdvei one: of. said. platensrelative to the other, a pair of concentric cylinders carried by the.movable: platen. and spaced radially toform an annular. chambertherebetween, amannular: piston disposed in. said chamber and slidable;between. Saidl'. cylinders, a second piston slidably disposed in. theinner cylinder, movable die; componentsactuated by both of said pistons,and separate means; to actuate each of said pistons; independently. oftherother and independently of the movementof the. movable platen. JOHND. GUELPH.

REFERENCES CITED The following'references are of record in the file ofthis" patent:

UNITED STATES PATENTS Name Date 1,724,332 Will etal Ans. 3. 1929

